The "canine first technique" in maxillary impacted canines: analysis of the treatment duration and success of therapy.

Objectives: The goal of the study was to analyze the eruption time of the maxillary impacted canines treated with the "canine first technique" and evaluate the success rate.

Materials and methods: A total of 103 patients with 131 impacted canines were treated. Alpha angle, Erickson-Kurol sectors, and age were studied to assess the difficulty of canine eruption. All the canines were treated with the "canine first" approach. The median follow-up time was evaluated using the Kaplan-Meier inverse procedure. The primary outcome (canine eruption time) was analyzed using Kaplan-Meier curves. The curve comparison between the different known risk factors was made using the log-rank test. The median eruption time (95% confidence interval) was calculated for each result.

Results: The majority of the canines (66.4%) were placed palatally and positioned in sector 3 (30.16%). The median alpha angle was 38.7°. In 88.9% of cases, canines erupted and the median time of eruption was 4.2 months. A statistically significant difference in alpha angle >/<22° able to influence the eruption time was assessed. The variation of the alpha angle (>/<22°) has found to be statistically significative when compared to the eruption time variation.

Conclusion: The canine first technique is effective for the eruption of impacted canines, and an alpha angle <22° can be considered a favorable prognostic factor.